Question

3. Which of the following is not a good example of a housekeeping protein in eukaryotic cells? a)DNA polymerase b)histones c)RNA polymerase 4)hemoglobin Explanation: 4. Which of the following statements about histones is true? a. Histones activate transcription when bound to the promoter, b. Although RNA polymerase can access DNA packed around histones, the general transcription factors and transcriptional regulators cannot. c. Histone acetyltransferases affect transcription by adding acetyl groups to histones and altering chromatin structure to allow accessibility to the DNA. d. Histone deacetylases remove lysines from histone tails. Explanation: 5. Which of the following is involved in post-transcriptional control of gene expression? a)micro-RNAs b)Histone acetylation c)Transcriptional activators d)Nuclear import receptors Explanation: /

Answer 1

1. DNA polymerase, histone, RNA polymerase are considered as house keeping protein in eukaryotic cell because they are involved in the primary functions of the cells.

Hemoglobin is essential for cellular respiration. So,it does not considered as house keeping protein.

2. Histone activate transcription when bound to the promoter.

Explanation: Covalent modification in histone N-terminals are required for the arrangement and as well as activation of the general transcription factors at that promoter regions.

3. microRNAs is involved in post transactional control of gene expression.

As miRNAs contain approximately 21 nucleotide long chain and genome encoded RNAs emerging as a key control in gene expression.It also controlled by hybridizing to target mRNAs and regulate the translation .